I don't know much about this, but it might be worth checking out.
--Matt

vBulletin News: vBulletin mobile app available for testing - Nov 15, 2010vBulletin iPhone app is available to test!
Recently we released our first version of our native iPhone application on vBulletin.com.
The app can be downloaded from here: http://www.vbulletin.com/go/iphoneapp
We would appreciate any of your feedback on the app.
Read more about the app here